MRK's ADC Candidate Gets FDA Breakthrough Therapy Tag for Lung Cancer

Group 1: FDA Breakthrough Therapy Designation - Merck's B7-H3-directed ADC, ifinatamab deruxtecan (I-DXd), received FDA's Breakthrough Therapy designation for treating extensive-stage small cell lung cancer in adults whose disease progressed after platinum-based chemotherapy [1][8] - The Breakthrough Therapy designation accelerates the development and review of drugs for serious conditions when early clinical evidence indicates significant improvement over existing treatments [2] Group 2: Clinical Studies and Data - The FDA's decision was based on data from the phase II IDeate-Lung01 study, which evaluated the safety and efficacy of I-DXd, supported by the phase I/II IDeate-PanTumor01 study [3][8] Group 3: Stock Performance - Year to date, Merck's shares have decreased by 15.3%, while the industry has seen a decline of 2.8% [4] Group 4: Collaboration and Development - Merck acquired global co-development and co-commercialization rights to I-DXd and two other ADCs from Daiichi Sankyo for a potential total consideration of up to $22 billion, although Daiichi retains exclusive rights for development in Japan [6][9] - I-DXd is also being evaluated in phase III studies for esophageal and prostate cancers, and it has an orphan drug designation for small-cell lung cancer in multiple regions [5][8] Group 5: ADC Market Competition - ADCs are viewed as a disruptive innovation in the pharmaceutical industry, enhancing cancer treatment by targeting tumors with cytotoxic drugs [11] - Daiichi Sankyo has multiple ADCs in clinical development and markets Enhertu in partnership with AstraZeneca, which is approved for various cancer indications [12] - Pfizer entered the ADC market by acquiring Seagen for $43 billion, adding several ADCs to its portfolio that have contributed significantly to its revenues [13][14]